Well, the Russians got fictional tanks in this game already. remote-controlled tanks, which don't require a crew, thus being able to completely give up crew
space for guns impossible to mount otherwise, saving weight for more armor and so on.
Not to mention the "Münchhausen" ammo which has far higher pen values at gold, then IRL, while others get the IRL for Gold and far worse for credit.

Yup, Panzer Front(PS1 and Dreamcast, Enterbrain studios, Japan, 2000) bonus tank, some smart guy put it on a website detailing German experimental tanks including the E-series and Maus without any kind of background checking for it.

One thing is having a fictional turret for a tank design that was half (only hull designed, not the turret), another one is adding a completely fantasy tank from another videogame... I can make up a lot of fantasy tanks but if they get placed ingame then the game itself goes down the tubes.